Valve tappet



- M31 1938. c. w. VAN RANST VALVE TAPPET Filed Sept. 19. 19:54

Patented May 24, 1938 UNITED STATES PATENTOFFICE VALVE TAPPET Cornelius W. Van Ranst, Detroit, Mich, assignor to Packard Motor Car Company, Detroit, Mich, a corporation of Application September 19, 1934, Serial No. 744,614

1 Claim. (Cl. 123-90) This invention relates to internal combustion engines and more particularly to valve tappets for such engines.

In the ordinary valve tappet construction, a

contact member is threaded into the body of the tappet and is held in adjusted position by a lock nut. In adjusting this contact member with relation to the body it is necessary to apply three wrenches, one to the body, one to the lock nut and one to the contact member. The body and contact. member are held from turning while the lock nut is loosened, the contact member and the body are then turned relatively to adjust the tappet after which the body and contact member are 5 held from turning while the lock nut is tightened.

The proper adjustment of the contact member is therefor rather diiilcult to effect and requires a considerable amount of labor and time.

One object of the present invention is to 1111-; no prove the construction and. mode of operation of adjustable valve tappets for internal combustion engines and to produce. an improved tappet construction in which any desired adjustment of the contact member with relation to the body of as the tappet may be effected, with the expenditure of a minimum amount of labor and time.'

Another object of the invention is to provide a novel valve tappet construction for internal combustion engines in which the contact member may be more quickly and easily adjusted with relation to the body of the tappet than could be done in prior constructions and will be held securely in adjusted position.

Another object of the invention is to provide an improved valve tappet construction for internal combustion engines in which the contact member maybe adjusted with relation to the body of the tappet and secured in adjusted position by the application of only two wrenches to the parts of. thetappet.

With the above and other objects -in view the invention consists in a valve tappet construction] embodying the novel and improved features herea inafter described and particularly pointed out in the claim, the advantages of which will be readily understood by those skilled in theart.

The invention will be clearly understood from the accompanying'drawing illustrating the invention in its preferred form and the following detailed description of the constructions therein shown.

In the drawing, Fig. 1 is a .view partly in vertical section and partly in front elevation illus- 55 trating a portion of an internal combustion englne provided with. a valve mechanism embodying the invention;

Fig. 2 is' a detail sectional view taken in' -a plane containing the axis of the valve tappet and illustrating certain of the parts of the tappet during 5 the process of manufacture, and 4 Fig. 3 is a detail sectional view taken in substantially the same plane as Fig. 2,;and illuk trating the parts ofthe tappet shown in'Flg. 2 at another-stage in the process of manufacture. m

The invention is illustrated in this application as applied to a valve of an internal combustion engine indicated as a whole at 2 andcomprises a cylinder 4, a piston 6 operating within the said cylinder, a valve 8 secured to the upper end of a 45 valve stem Hi mounted for longitudinal 'reclpro-yj eating movementin a guide I2 formed on the engineblook. The valve stem is moved in one directionlin the guide 12 by means of a coiled spring 14 surrounding the valve stem and inter-l go posed between a washer l6 engaging theengine,

block and a retainer disk ll held against longi-a,

tudinal movement on the valve stem. 7

The valve tappet comprises a tappet body mounted for axial reciprocating movement in a guide or bearing 22 formed on-the engine block. The lower end of. the tappet body is engaged by. p a cam 24 mounted on a cam shaft 25. Thetappet alsocomprises a contact member mounted on the upper end of the tappet body for engage- 30 I ment with the lower end of the valve stem. Inorder that this contact member may be adjusted axially with relation to the t ppet body 10, the contact member is threaded into said The contact member 28 is held or locked in. adjusted 35 position by means ofan annular locking' disk 28 threaded on the lower end of the contactmembe'r. This-. locking disk is made of spring metal and normally hassubstantlally the concavo convex I or cupped shape in cross section shown in 40 Fig. 2 The body of the tappet is made in two parts as indicated respectively at 20a and 20b, these parts being secured together preferably by welding-as indicated at 30 in Fig. l. The part Ila is formed with an end wall having a central opening 33. In threading the cupped disk ll and the body of the tappet, before the parts 20a and 20b of the tappet are assembled and secured together, the cupped disk is inserted in the part Ila in contact with the end wall 32 thereof as shown Ila and engaging the cupped disk. while the disk is in this position, a tap it is inserted in the tool 84 and is passed through the openings in the cupped disk and in the end wall 32 of the part 20 oi the tappet to thread these parts for the reception oi the contact member 2!.

After the part 20a and the locking disk have been thus threaded, the contact member 26 may be assembled with the part 28a the tappet by removing the tap and screwing the contact member into said part and into'the locking disk ll while said disk is held flattened against the end wall 8!. The tool I4 is then removed and the parts lla'and 20b are assembled and welded together.

With the above construction, the contact member and the tappet body may be quickly adjusted relatively by applying a wrench to each of these parts and turning relatively the said parts. The contact member will be securely held in adiusted position after each adjustment by the resilience of the locking disk which tends 'constantly to move the contact member axially with relation to the body 20 oi the tappet.

In the operation of the valve operating mechanism the forces exerted on the contact member which are produced by the reaction of the valve stem on the same during the upward movement oi the valve under the action 01 the cam 24, and during the downward movement of the valve under the action of the spring ll tend to force said member downwardly with relation to the body Iloi' the tappet. The resilience oi the cupped disk II also tends to force said contact member downwardly with relation to the body II and to press the threads of the contact member against the threads on the tappet body and also to press the threads of the locking disk against said contact number. The frictional contact between the threads of the contact member and respectively the threads of the body of the tappet and the threads of the locking disk prevents the turning 01' the contact member with relation to said body.

In the above construction the forces exerted on the tappet body 20 and the contact member It during the operation of the valve operating mechanism tend to move relatively the said members axially in the same direction as the force exerted by the locking disk 28 tends to move relatively said members. The valve operating mechanism therefor has no tendency to overcome the force exerted by the locking disk and it is necessary to construct said disk so that, when compressed, it exerts only a relatively light force axially on the contact member and tappet body.

It is to be understood that the invention is not limited to the particular construction and arrangement of parts oi. the illustrated embodiment of the invention, but that the construction shown and-described is merely illustrative of the invention and that the invention may be embodied in other forms within the scope of the claim.

Having explained the nature and object of the invention and having specifically described a construction embodying the invention in its prei'erred form, what is claimed is:

In a tappet for internal combustion engines, the combination of a. body portion having an apertured end wall, said end wall being threaded at the aperture, a spring metal disk arranged against the inner face of said end wall, said disk in its nonnal state being cup-shaped, and said disk having an aperture with threads in the aperture so formed that when the disk is in a flat state the threads correspond exactly with the threads in the aperture of said end wall, said spring metal disk being in a flat state with its normally concave face against the inner face of said end wall, and a threaded adjustment member extending through the apertures oi. said end wall and said disk and in intimate threaded contact with both, whereby the adjustment member retains said disk in its fiat state and the disk acts to Irictionally lock the adjusting member in adjusted position.

CORNELIUS W. VAN RANST. 

